وَيَحْلِفُونَ بِٱللَّهِ إِنَّهُمْ لَمِنكُمْ وَمَا هُم مِّنكُمْ وَلَٰكِنَّهُمْ قَوْمٌ يَفْرَقُونَ
Important Words:
یفرقون (are timorous) is derived from فرق which means, he feared or was afraid or he became frightened. They say فرقت منكi.e. I feared thee or I was in fear of thee. فرق علیه means, he feared for him. فرق also means, he entered into a wave and dived therein (Lane).
Commentary:
As the Muslims predominated at Medina, the hypocrites who lacked moral courage had to conceal their infidelity and even outwardly became Muslims to secure worldly advantages. They had no faith in their hearts, but they did not possess the courage to openly give vent to their real feelings.